Low power, high performance circuits are often plagued by power supply related issues. This common occurrence is frequently due to mythical (or misapplied) rules-of-thumb. These rules of thumb often lead us in the wrong direction, making things worse rather than better. In this article, I’ll highlight some of the most common mistakes engineers make and share some fundamental rules for designing clean power for sensitive circuits. Applying these rules will result in higher performance, lower cost designs with fewer design iterations.